This invention relates to the field of data storage and retrieval and, more particularly, to improvements in apparatus for protectively packaging disk-shaped data storage media.
The need to protect the delicate recording surface of a data storage disk (e.g. optical, magnetic, and magneto-optic disks) is self-evident. In the commonly assigned U.S. application Ser. No. 923,509, filed Oct. 27, 1986 entitled "Carrier For Data Storage Disk" in the names of D. Stark et al, there is disclosed a protective package for a rigid optical disk. Such package comprises the combination of a disk "carrier" which surrounds the periphery of the disk and supports the disk at spaced locations about the disk periphery, and a protective cartridge or "caddy" which comprises a relatively rigid, box-like structure that totally encloses the disk/carrier assembly. One end of the protective cartridge is provided with a pair of spring-loaded doors which permit entry of the disk/carrier assembly into the cartridge interior. In response to a door-opening force, such as applied by the leading edge of the disk/carrier assembly as it moves in a direction to enter the cartridge interior, the cartridge doors swing inwardly. As the disk/carrier assembly slides into the cartridge, the cartridge doors ride on a protruding bearing surface of the carrier so as not to contact the recording surfaces of the disk. After the trailing edge of the disk/carrier assembly has cleared the cartridge doors, the doors swing to their normally closed position, thereby capturing the disk/carrier assembly within the cartridge.
In disk packages of the type described above, it will be appreciated that the cartridge interior must be somewhat longer than the length of the disk carrier in order to provide clearance for the cartridge doors to swing closed behind the entering disk/carrier assembly. This space requirement translates into a relatively loose fit between the disk/carrier assembly and the cartridge interior, allowing the disk/carrier assembly some degree of freedom to slide longitudinally (i.e. forward and backwards) within the cartridge interior. While this movement is relatively small, any substantial movement of the disk/carrier assembly within the cartridge interior can be detrimental to the structural integrity of the relatively delicate data storage disk.